Use auth_token from keystonemiddleware
Use auth_token from keystonemiddleware

auth_token middleware in python-keystoneclient is deprecated and has
been moved to the keystonemiddleware repo.

Closes-Bug: #1342274

Change-Id: I1aadbe24db63eb2507b088cd53886d7f2e192cab

Tehsmash/networking-cisco-nexus